"GNOME 3.4 introduces a range of new features. A new document search facility allows quick access to content stored both on your device and online. Smooth scrolling means that moving through content is slick and graceful. New application menus, which are located on the top bar, provide a useful way to access application options and actions." And a lot more.

All the Gnome 2.x using people I know, me included, have jumped ship: sadly some of them have gone back to Windows, nobody is using Unity either.

So, as far my little anecdotical evidence goes, it's more 100% than 80% or 90%. Of course it is nearly impossible to have more precise figures, and in all fairness there are people who seem very happy with Gnome Shell / Unity. But I remember the Gnome 1.x > 2.x controversy and this looks much more serious both in numbers and wrt the issues at stake (it's not simply a matter of lost features and/or regressions, it's the new UI paradigm that has driven many people away).

Today I still follow Gnome development as that's the foundation of Cinnamon, but that's it.

Not just the UI paradigm, I think, but also some technical decisions that just do not make sense on a desktop computer running Linux, such as mandatory GPU compositing, hiding the power off button (though thankfully it seems they have brought it back recently), huge icons in a mouse-driven interface, half-assed window management facilities...

It seems that when designing Gnome 3, the Gnome team took much care into producing a high-quality interface for tablet computers, without much consideration to desktop user experience. What they apparently forgot, however, was that almost no one uses Linux on a tablet.

People keep speaking about this GNOME 1.x to 2.x controversy. In my opinion, it was not anything like this now. I remember very well. The paradigm was the same, menus and sub-menus. They just had rearranged the menus and used two panels. Now this is an entire different paradigm. Not true when comparing to that transition in 2001.